Key blank



FIG. 1 is a side elevational view of a key blank showing my new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a top perspective view thereof;

FIG. 4 is a front end elevational view thereof;

FIG. 5 is a rear end elevational view thereof. 

The ornamental design for a key blank, as shown. 